Ancient crustacean had elaborate heart

The 520-million-year-old crustacean F. protensa had a complex system of blood vessels that connected its body and brain. Part of what was once the animal’s gut appears as dark stains along the animal's midline. 

X. Ma

The early ancestors of insects, centipedes and crustaceans had big hearts.

A fossil from 520 million years ago shows that the now-extinct Fuxianhuia protensa had a broad spindly heart that extended into a complex system of arteries, which sent blood to the creature’s limbs and organs, including its brain, eyes and antennae. The new 7.6-centimeter-long fossil from Kunming, in southwest China, represents the earliest complete cardiovascular system found in an arthropod, Xiaoya Ma of London’s Natural History Museumand colleagues report April 7 in Nature Communications. The discovery adds to F. protensa’srecord-breaking status: It also has one of the oldest brains identified to date (SN: 11/17/12, p. 11).

The structure of F. protensa’sblood vessels was similar to, and in some cases more complex than, what’s seen in modern crustaceans, suggesting that the ancient creature’s cardiovascular system may have provided the evolutionary basis for ones that developed in later crustaceans. The complex cardiovascular system may also have supported F. protensa’s sophisticated brain, giving the animal reasonably good senses of sight and smell to forage the oceans for food, the scientists write.

A diagram of F. protensa shows its cardiovascular system (red) and gut (green) running the length of its body. The cardiovascular system attaches to the animal’s gut, its brain and its central nervous system (blue). Nicholas Strausfeld
F. protensa‘s entire cardiovascular system, including its heart (center), appears in this image of the fossil from China. X. Ma
The 520-million-year-old crustacean F. protensa had a complex system of blood vessels that connected its body and brain. Part of what was once the animal’s gut appears as dark stains along the animal’s midline. X. Ma

Ashley Yeager is the associate news editor at Science News. She has worked at The Scientist, the Simons Foundation, Duke University and the W.M. Keck Observatory, and was the web producer for Science News from 2013 to 2015. She has a bachelor’s degree in journalism from the University of Tennessee, Knoxville, and a master’s degree in science writing from MIT.

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